What's the origin of the word 'noise' in photography?

I know we can also use the word grain which conveys the same meaning and which makes more sense in my opinion. But I noticed photographers have a preference for the term 'noise'. What's got the word 'noise' to do with something that is visual not aural. Interestingly, same thing in French - the grain is called 'bruit' (noise).

A google search wasn't much helpful.

Also, is the term specific to digital photography (actually where I encountered the term) or film photography as well?

Any idea?

According to Wikipedia the term is used by analogy to acoustic noise:

Image noise:

• is an undesirable by-product of image capture that adds spurious and extraneous information.

• The original meaning of "noise" was and remains "unwanted signal"; unwanted electrical fluctuations in signals received by AM radios caused audible acoustic noise ("static"). By analogy unwanted electrical fluctuations themselves came to be known as "noise".Image noise is, of course, inaudible.

The expression "image noise" appears to have been used from the late 60's early 70's according to Ngram.

Early usage example:

• Some workers have judged gains over unaided photography in terms of the relative rates of photographic blackening. Image noise has often been ignored. Image resolution has either been quoted as an independent parameter, or it has been ....From Advances in Electronic & Electron Physics 1969.

Noise clearly visible in an image from a digital camera

Noise is a noun whose principal meaning relates to sound.

But it also has many extended meanings e.g. concerning scandal, rumour or report.

And it is used to express importance (Hoggett is now a big noise in the dental-supplies industry) and many other things.

But the extended use you are asking about relates to sense 11a in the OED.

11.a. In scientific and technical use: random or irregular fluctuations or disturbances which are not part of a signal (whether the result is audible or not), or which interfere with or obscure a signal; oscillations with a randomly fluctuating amplitude over a usually continuous range of frequencies. Also (in extended use): distortions or additions which interfere with the transfer of information.

The phrase "noise" was non-existent in photography until the video/digital age. Since much of the signal processing conundrums involves the introduction of "bad stuff" during transmission, and transmission is essentially a signals domain, the word "noise" stuck.